The present invention relates to emollients, particularly emollients used in conjunction with cosmetic and pharmaceutical products that are externally applied to patients. The present invention particularly relates to the provision of oxidatively stable emollients produced from moringa oil or its derivatives.
Emollients are materials that are applied to the skin of subjects to produce softness or smoothness. They have been used for centuries in both cosmetic and pharmaceutical products. The original emollients were extracts or directly concentrated materials from plants or animals, while modem emollients also include partially synthetic (derivatives of natural products) or completely synthetic materials. The natural emollients, for the most part, have tended to provide a wet or oily feel and appearance to the skin of humans. The synthetic and partially synthetic emollients have been tailored to provide the specific type of appearance and feel desired in an end product. Even with this tailoring, there are only a few synthetic emollients that provide a highly satisfactory dry feel. Silicon emollients are the most successful dry-feel emollients.
In recent years there has been an increasing attempt in many commercial fields to use natural products from renewable sources or at least naturally derived products. In part this effort has been through use of natural biodegradable materials that require a minimum amount of processing initiated to help reduce pollution of the environment. Silicones tend to be a class of synthetic material that is not easily degraded by the environment. The trend towards the use of natural biodegradable products in cosmetics provides motivation for manufacturers and compounders to seek alternatives to even the more successful synthetic components of their products, including silicon emollients.
In addition to the feel of an emollient, cosmetics and their ingredients must exhibit stability, both in storage and in use. The cosmetics must not deteriorate or separate in storage and use, and the individual ingredients should not decompose or otherwise undergo chemical changes that alter their desirable properties. One of the more common susceptibilities of products or components to ambient damage is from oxidation, and natural materials are clearly, through observation, susceptible to oxidation, as is commonly seen by browning of fruit exposed to air or the rancid smell of old vegetable oils. Many foods, food additives, cosmetics, fragrances, medicaments, and colorants are well known to be subject to damaging effects from oxidation.
The most frequent means of reducing the effects of oxidation (including light amplified or stimulated oxidation) include oxygen excluding packaging (e.g., bottles, cans, oxygen impermeable polymer wraps, and the like.), chemical modifications of the ingredient to reduce its tendency toward oxidation while minimally altering its functional properties, and the addition of antioxidants to directly quench oxidative species before they oxidize the ingredient. Packaging controls are most effective where a product is to be used once, as when the package is opened, air is introduced into the container and the package provides no complete protection against contact with oxygen. Chemical modification of an ingredient offers more general protection, assuming that a modification can be devised that both substantially reduces the tendency towards oxidation and also maintains the functional properties desired in the selection of the underlying chemical. This can be an exhaustive task, with no guarantees of success.
The use of antioxidants offers a general approach to the oxidation problem for a wide variety of materials and fields including the protection of edible materials against premature oxidation. The use of antioxidants would appear to some to require little more than the appropriate selection of an antioxidant sold commercially for specific purposes to achieve a commercially viable product with a necessary level of oxidation resistance. However, antioxidants may have and often display unique interaction with other ingredients and with the primary component on either a physical level (by not blending with the other materials), on a chemical level by reaction with active ingredients, or both. It is therefore necessary, with some compositions that require antioxidant protection, to conduct extensive research with no assurance of success. There are also such a wide variety of classes of antioxidants and so many variants within the classes that a search for an appropriate antioxidant is a highly problematic search, and the desire for the best antioxidant assures a time consuming process.
Among the more common classes of antioxidants are free-radical terminators, particularly those with available hydrogens from phenolic hydroxyl groups. Within that single class are the subclasses of butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), hydroquinones (such as tertiary-butylhydroquinones, propyl gallate, and tocopherols). Reducing agents or oxygen scavengers encompass another class of antioxidants and includes ascorbic acid (vitamin C) and its derivatives (such as esters of ascorbic acid, such as ascorbyl palmitate); sulfites (such as sulfur sulfite, alkali metal sulfites, and bisulfites, including alkali metal bisulfites); glucose oxidase (including catalse); erythrobic acid and its derivatives. Chelating agents comprise another class of materials that have been used to address problems with potentiators of oxidation and include citric acid (and its derivatives), polyphospages, and aminopolycarboxylic acids (such as ethylenediaminetetraacetic acid (EDTA). Finally, there are other antioxidant classes with less general areas of use.
The use of polyglycerol esters as oil in water (o/w) emulsifiers for cosmetic formulations is described, for example, in J. Soc. Cosmet. Chem. 28, 733-740 (1977) and in Fette, Seifen, Anstrichmettel 88, 101-106 (1986). In addition, the use of selected polyglycerol fatty acid esters as cosmetic emulsifiers is claimed in DE-A1 40 05 819 and DE-A1 40 23 593 (BASF). However, in cases where the esters based on unsaturated or saturated fatty acids mentioned in these documents are used, it has been found that the resulting emulsions are not always sufficiently stable in storage and/or are low in viscosity, i.e. have a viscosity that is not sufficiently high, so that problem-free dosing is difficult. The invention of that reference relates to cosmetic and/or pharmaceutical formulations that are characterized in that they contain statistical monoesters of technical triglycerol with saturated C16-C18 fatty acids as emulsifiers, the monoester content being from 30-50% by weight. It was asserted that it was surprising that the degree of self-condensation of the oligoglycrols in conjunction with the nature of the fatty acid and the percentage content of monoesters has a critical bearing on the properties of the resulting emulsifiers. That invention includes in particular the observation that the establishment of a percentage monoester content of 30-50% in the emulsifiers according to the invention leads to a significant improvement in storability and viscosity compared with otherwise known products of the prior art.
The Moringa family reportedly consists of approximately 10-14 Xerophytic species distributed from tropical Africa to the East Indies. Several species exist including Moringa concanensis, Moringa oleifera, Moringa drouhardii and Moringaperegrina. 
Interest in the oil extracted from M. oleifera, known commercially as xe2x80x98Benxe2x80x99 or xe2x80x98Behenxe2x80x99 oil, has existed for well over a century. In 1817 a petition containing particulars relating to the oil from M. oleifera was presented to the Jamaican House of Assembly. The petition described the oil as being useful for salads and culinary purposes and to be equal to the best Florence oil as an illuminant giving a clear light without smoke. A subsequent paper presented to the Jamaica Society of Arts in 1854 described how samples of oil had been tested by two watch making establishments in Kingston and had been reported to be equal to the expensively imported xe2x80x98watch oilxe2x80x99. Subsequent reports indicated that the oil was used extensively as a lubricant until being replaced by sperm-whale oil. The oil was said to have unique properties being able to resist becoming rancid. However, this is not the case, the oil will eventually turn rancidxe2x80x94as indeed will all vegetable oils. The oil has also been reported to have been used extensively in the xe2x80x98enfleuragexe2x80x99 process whereby delicate fragrances are extracted from flower petals. There are references to the current use of the oil in the cosmetic industry and to its use for culinary purposes, however, there is no evidence to support this.
The first recorded study of the composition of the oil was carried out in 1848, which revealed a fatty acid with a high melting point. This was subsequently called behenic acid from which the commercial name for M. oleifera oil came. Over the years a number of different studies have been carried out to determine the composition and characteristics of the oil. The oil produced is pale yellow in color, non-drying with a mild, characteristic nutty flavor. The seed kernel contains on average 40% by weight oil, the fatty acid composition of that has been determined in a number of studies. The table below provides details obtained from the most recent of these. The variation in composition and quantity of the individual fatty acids arises primarily from differences in the variety of seed analyzed and the analytical techniques used.
As the table shows, the fatty acid composition is considered to be similar to that for olive oil and as such suitable is considered suitable for edible purposes. More recently the oil has also been shown to be particularly effective in the manufacture of soap producing a stable lather with high washing efficiency.
The presscake obtained following oil extraction may be utilized as a fertilizer. Its use as a potential animal feed has, in the past, not been recommended as it contains an alkaloid and a saponin. Work is currently being carried out to verify this and, if necessary, to determine suitable methods for detoxification. A recent finding has been that the presscake still contains the active fractions that may be utilized as a water treatment chemical.
Juice from fresh moringa leaves can be used to produce an effective plant growth hormone, increasing yields by 25-30% for nearly any crop: onions, bell pepper, soya, maize, sorghum, coffee, tea, chili, melon, etc. One of the active substances is Zeatin, a plant hormone from the Cytokinines group. This foliar spray should be used in addition to (and not in lieu of) other fertilizers, watering and sound agricultural practices. In one trial, use of this spray increased maize yields from 60 to 130 sacks per hectare.
Using moringa as a green manure can significantly enrich agricultural land. In this process, the land is first tilled. Moringa seed is then planted 1-2 cm deep at a spacing of 10xc3x9710 cm (a density of one million seed per hectare). The density can be greater. The only limits to plant density are availability of seed, water and fertilizer. After 25 days, the seedlings are plowed into the soil to a depth of 15 cm. The land is prepared again for the crop desired. Seeding can be done mechanically if the seed is first de-hulled.
Moringa leaves can be used as cattle feed (beef and milk cows), swine feed, and poultry feed. With moringa leaves constituting 40-50% of feed, milk yields for dairy cows and daily weight gains for beef cattle increased 30%. Birth weight, averaging 22 kg for local Jersey cattle, increased by 3-5 kg.
There are reports of moringa being used in cosmetic preparations as far back as 1400 BC, wherein an allegedly successful remedy to treat wrinkles consisted of: gum of frankincense wax; fresh moringa oil; Cyprus grass. The mixture was ground finely, mixed with fermented plant juice, and applied daily. In modem cosmetic products, moringa oil can be used effectively in skin- and hair care products as a stable emollient with a pleasant skin feel and special fragrance-fixing properties.
The novel features that are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its structure and its operation together with the additional object and advantages thereof will best be understood from the following description of the preferred embodiment of the present invention when read in conjunction with the accompanying tables. Unless specifically noted, it is intended that the words and phrases in the specification and claims be given the ordinary and accustomed meaning to those of ordinary skill in the applicable art or arts. If any other meaning is intended, the specification will specifically state that a special meaning is being applied to a word or phrase. Likewise, the use of the words xe2x80x9cfunctionxe2x80x9d or xe2x80x9cmeansxe2x80x9d in the Description of Preferred Embodiments is not intended to indicate a desire to invoke the special provision of 35 U.S.C. xc2xa7112, paragraph 6 to define the invention. To the contrary, if the provisions of 35 U.S.C. xc2xa7112, paragraph 6, are sought to be invoked to define the invention(s), the claims will specifically state the phrases xe2x80x9cmeans forxe2x80x9d or xe2x80x9cstep forxe2x80x9d and a function, without also reciting in such phrases any structure, material, or act in support of the function. Even when the claims recite a xe2x80x9cmeans forxe2x80x9d or xe2x80x9cstep forxe2x80x9d performing a function, if they also recite any structure, material or acts in support of that means of step, then the intention is not to invoke the provisions of 35 U.S.C. xc2xa7112, paragraph 6. Moreover, even if the provisions of 35 U.S.C. xc2xa7112, paragraph 6, are invoked to define the inventions, it is intended that the inventions not be limited only to the specific structure, material or acts that are described in the preferred embodiments, but in addition, include any and all structures, materials or acts that perform the claimed function, along with any and all known or later-developed equivalent structures, materials or acts for performing the claimed function.
Compositions or fluids comprising oils or waxes derived from the moringa plant, bean, seed and/or nut can be provided with a surprisingly large increase in oxidation stability by their combination with mixtures of particular classes of antioxidants, particularly the combination with at least a tocopherol. The stabilization combination, according to the present invention, is particularly effective when the long-chain organic molecules comprising moringa oil having less than 1% methylene interrupted polyunsaturation. Even more surprising is the dramatically large increase in oxidation stability when a supplemental additive selected from the group comprising malic acid, kojic acid, and ascorbic acid, is further included into the combination. The tocopherol is preferably present in an amount of from 0.01 to 5% by weight of the composition and the at least one supplemental additive is preferably present in an amount of from 0.01 to 2% or more by weight of the composition.
Described herein, by way of example of the inventive composition, is an emollient that is comprised of oil, or derivatives hereof, produced from the moringa plant in combination with an oxidation stabilizing system comprising at least one tocopherol. The emollient using the composition of the present invention is oxidatively ultra-stable relative to emollient compositions that do not include the oxidation stabilizing system of the present invention. Preferably, the oils, and their derivatives, produced from the moringa plant should have a percent methylene interrupted unsaturation of less than 1%. Herein, xe2x80x9cderivativesxe2x80x9d of moringa oil means oils produced from the moringa plant that are further processed to create such as moringa oil methyl ester, moringa oil ethyl ester, moringa oil isopropyl ester, and the like.
Ethyl esters of oils, particularly from triglyceride oils are commercially available from a number of different sources and are available from many different natural material sources, such as for example: Kukui Nut (Aleurites Molucunna) oil ethyl ester; Borage seed oil (Borago Officinalis) ethyl ester; Hazelnut (Corylus Avellana) oil; Sweet Almond oil; Apricot kernel oil; the ethyl ester of arachidonic acid (5,8,11,14-Eicosatetraenoic acid ethyl ester); Avacado ethyl ester (ethyl perseate); ethyl esters of isostearic acid, lactic acid, lauric acid, myrisic acid, stearic acid, palmitic acid (hexadecanoic acid), ricinoleic acid (12-hydroxy-9-octadecanoic acid), and linoleic acid; Mink oil ethyl ester (ethyl mustelate); olive oil ethyl ester (ethyl olivoleate); ethyl ximenynate (ethyl santalbate); silybum marianum ethyl ester (derived from silybum Marianum oil); and the like. These ethyl esters are readily manufactured from the base oils by conventional reactions with ethanol (preferably anhydrous ethyl alcohol) and an esterification catalyst. Many of these oils, and their ethyl esters, are primarily indicated as skin-conditioning agents and/or emollients with the individual esters varying in their chemical characteristics, substituent groups, molecular weights, and degrees of methylene interrupted unsaturation. However, these materials have been found to have their oxidative stability dramatically shortened by the ethyl esterification.
The characteristic of the degree of methylene interrupted unsaturation has some particular significance for the selection of preferred materials in the practice of the present invention, with moringa oils, and their derivatives, having less than 1% methylene interrupted unsaturation being most desirable. The term xe2x80x9cpercent methylene unsaturationxe2x80x9d is used as a description of the internal structure of these various components of the oils, such as triglycerols and esters. The term literally means the weight percent of acyl groups having double bonds separated by or interrupted by a methylene group, xe2x80x94CH2xe2x80x94. This term is used to better explain the reactivity of fatty acyl groups whose double bonds are so far away from one another that they behave chemically as monoenoic fatty acyl groups. For example, consider the double bonds at the detla-and detla-13 position of meadowfoam oil. The double bonds are so remote from each other that the acyl group acts as if it were monenoic. The two double bonds do not interact in a way that would cause the fatty acid group to behave as a dienoic molecule rather than as an onenoic molecule. The weight percent of acyl groups having double bonds separated by a methylene group is calculated, then added to other such acyl groups to determine the total percent methylene interrupted unsaturation. Soybean oil, for example, has two such acyl groups, the linoleic and linolenic groups. The weight percentages of these two acyl groups in soybean oil is usually 52% and 6%, respectively. The percent methylene interrupted unsaturation is therefore 58%.
All oils, and their derivatives, oxidatively degrade. Their oxidative stability is measured and compared using an oxidative stability index (OSI, as outlined in The Official and Tentative Methods of the American Oil Chemists"" Society, AOCS Method Cd 12b-92). Use of the most common antioxidants (e.g., BHA and BHT, for example) with these natural long-chain oils (e.g., from at least about 8 carbon atoms to 30 or more carbon atoms in the primary aliphatic chain), and their ethyl esters, fats or fatty materials tends to slightly improve their oxidative stability, but do not provide dramatic improvements in levels of OSI in these oils. However, there is always a demand for compositions that exhibit longer and longer oxidative stability. Therefore, there is therefore a clear need for the ability to provide an oxidatively ultra-composition for uses in emollients and the like.
Pure moringa oil has an oxidative stability of 29.6 hours. According to data on other natural oils, the addition of a small amount of a tocopherol should increase the oxidative stability of the oil by about 150%. Thus, one of ordinary skill in the arts would expect that the addition of a small amount of tocopherols to moringa oil would increase its oxidative stability from 29.6 to around 44.4 hours. While this slight theoretical increase may be beneficial, it has been unexpectedly determined that the actual increase in oxidative stability is 133.3 hours, or an increase of 450%. This dramatic increase is extremely useful for compositions such as emollients since it extends the emollient shelf live significantly beyond that that of any other natural, or naturally derived, emollient composition. Moreover, it has been surprisingly determined that further addition of a supplemental additive extends the oxidative stability even more.
Thus, the present invention provides emollient compositions displaying drastically improved oxidation resistance comprising moringa oil (or derivatives thereof), fats, or fatty material, and at least one tocopherol. The tocopherols may be used in amounts from about 0.02% by weight of the composition to about 5% by weight of the composition, depending upon the particular formulation, and other additives in the composition. In general, relatively low amounts of the tocopherols are highly effective.